UPGRADE YOUR BROWSER

We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 38844

Digital Pre-Distortion (DPD) Reference Design v3.x/v4.x - How do I write and read coefficients from the core?

Description

For the Digital Pre-Distortion (DPD) v3.x/v4.x, how can I write to and read from the coefficients?

Solution

In DPD v3.x and DPD v4.x, there are three coefficient sets (per transmit path) used when DCL_MODE is set to one, and a single set used when DCL_MODE is set to zero. When DCL_MODE is zero, the only active coefficient set for each transmit path is set 0.

The coefficients values can only be accessed while DCL is disabled.

Reading coefficients sets:

* Write desired transmit path (port) to read coefficients from to address PORTNUM[2] in the host interface.
* Write desired coefficient set number to address 4. There are three sets available (0, 1 or 2).
* Trigger DPD command 30.
* Read values from the host interface:
o For DPD v3.x address 384 through to 441 (58 values). This is the coefficient set, the format of the data is not defined since doing so could expose the underlying architecture of DPD.
o For DPD v4.x address 380 through to 511 (132 values). This is the coefficient set, the format of the data is not defined since doing so could expose the underlying architecture of DPD.


Loading coefficient sets:

* Write desired tx path (port) to write coefficients to in address 2.
* Write desired coefficient set number to address 4. There are three sets available (0, 1 or 2).
* Write values
o For DPD v3.x, write the 58 values read during the "Reading coefficients sets" process into registers 384 thru 441.
o For DPD v4.x, write the 132 values read during the "Reading coefficients sets" process into registers 380 thru 511.
* Trigger DPD command 31. This command loads the coefficients into the Micro-Blaze memory, but does NOT load them into the DPD filter.
* (optional) Trigger command 8, 9 or 10 to load the desired coefficient set into the DPD filter.


For a detailed list of Digital Pre-Distortion (DPD) Release Notes and Known Issues, see (Xilinx Answer 33521).
AR# 38844
Date Created 11/01/2010
Last Updated 11/18/2010
Status Active
Type General Article
IP
  • Digital PreDistortion(DPD)